Electromagnetic vibrator.



UNITED sTATEs PATENT OFFICE.A l

WOLFGANG E. SCHWARZMANN ANDACHALRLES M; WILD, OF SPRINGFIELD, MASSACHU- SETTS, ASSIGNORS TO BOSCH MAGNETO COMPANY, A CORPORATION F NEW YORK.

ELECTROMAGNETIC VIBRATOB.

Specification of Letters Patent.

Application inea August 1o, 1914. serial N0. 856,042.

of Springfield, county of Hampden, and' State of Massachusetts, and CHARLES M.

WILD, a citizen of the United States, residing at and whose post-cnice address is No. 14 Springfield street, in the city of Springfield, county of Hampden, and State of Massachusetts, have invented certain new and useful Improvements in Electromagnetic Vibrators; and we do hereby declare the following to be a full, clear, and exact description ofthe invention, such as will enable others skilled .in the art to which it appertains to make Iand use the same. The object of the present invention is to provide an improved electromagnetic vibrator suitable for use in electrical ignition systems for internal combustion engines, and particularly a vibrator for this' purpose wherein the vibratory armature is capable of operation at high Jrireiniency over prolonged periods without freezing or sticking at thecontacts even when a lcomparatively high voltage is applied -tc the terminals. Although a vibrator having these characteristics is of general utility in eleotrical ignition systems and for other purposes7 yet it is particularly useful for supplying current during starting to the primary winding oit a magneto to generate ignition voltages in the secondary winding thereof satisfactory for producing sparks at the spark plugs to ignite the combustible mixtures present in the cylinders. By supplying interrupted currents of high frequency 40 to the magneto,v the current required is proportionately reduced, thus reducing the size of the battery or other source of current for the purpose. Furthermore. by rendering the cooperative contacts `safe against freezing 45 and sticking,` failure to disconnect the battery immediately after the engine has'started up under its own power does not introducev unreliability and failure in the succecding starting periods. The vibrator dis-i closed herein not only meets these requirements, but the construction lends itself to association with a condenser in a closed housing which not only protects the working parts -from exposure and against the en- 65 trance of water and dirt, but provides access for adjustment of the vibratory armature and the cooperative contact terminals.

These and other advantages will be pointed out in the following description and in the appended claims, taken in connection with the accompanying drawings, in which- Figure, l represents a central vertical-,section of a vpreferred embdiment within our invention; Fig. 2 represents a view, mainly in section on line 2-2 of Fig. l, but partly -in elevation; Fig. 3 represents a section on line 3-3 of F' ig. l; Fig. 4f represents a top view of the magnetic core particularly showing the pole pieces thereof; and Fig. 5 is a wiring diagram of the vibrator.

Themagnetic core l is shuttle-shaped and comprises the cross bar 2 and the side flanges 3 integral therewith, the pole pieces 4 thereof being fastened at 5 tothe side flanges and providing an air gap at 6 inthe magnetic circuit. T he n'iagnetizing coil 'i' is wound on the cross bar, and a plate condenser' 8 of circular outline with straight sides resting Patented J an. 9, 1917.

against the inner parts of the side flanges 3 is held between the top of the magnetizing coil and the under side of the pole pieces by a bolt 9 passing through the condenser plates and through one of the pole shoes. The outer faces of the side flanges are screwthreaded at lO for engagement with a support made up of an internally-threaded brass ring ll anda cover l2 of insulating material. The upper part Yof the ring is serrated. at 13 so as to be lightly held against turning by the curved spring finger 14 at any position to which the support may be adjusted. 'Ihe continuous groove 15 is cult in` the Ting. and in this groove loosely sets the vibratory armature comprising the I- shaped steel diaphragm 16 and an iron button 17 bridging the gap 6 in the magnetic circuit, but normally held away from contact with the pole pieces by the spring action of the diaphragm. The button 17 is riveted to the lniphragm and a contact terminal 18 of platinum is mounted on the upper side 0f 'the rivet. A flanged brass sleeve flanged disk 25 of Waterproof insulating inaterial is fastened by the screws 26 to the base plate, while the fiber disk 27 and 'the' vibrator is tightly closed to the outside against the entrance of water and dust, the continuous recess 29 serving to deflect from the joint of the disk 25 any water which may get underneath the base plate. The holes 30 provide for screws for fastening the vibrator to the dashboard of an automobile or other support. The steel hood 31 oi the housing has screw threads engaging the screw threads of the upstanding rim 23 of the housing base, and is provided with a tapered. locking end portion 32 designed to tightly lit a beveled seat in the opstanding rim to thereby provide a water and dust tight connection. between the hood and the housing base. l

As shown particularly in Figs. 2 and 5, one terminal of the magnetizing coil 7 is electrically connected by the wire 33' to the binding post 34, which is insulated from but fastened to the housing base. The insulated binding post 35 is electrically connected by the wire 3G to the insulated plates of the condenser 8, and also by the branch wire 37 to the screw 20 carrying the contact terminal 21. The contact terminal 1S is grounded on the magnetic core through the vibrator diaphragm 1.6 and the ring 11, while the other plates oi' the condenser are grounded thereon through the bolt f) and a pole piece 4t. The other end of the magnetizing coil 7 is grounded directly on the core.

The support carrying the vibratory armature is'screwed down on the magnetic core until the proper clearance exists between the button 17 and the pole pieces 4, the spring linger 14 maintaining` the adjustment. Then r the screw 20 is adjusted and locked in such position that the contact terminal 2l'lightly engages the contact terminal 18. Now when the binding posts 34, 35, are electricallj,Y connected to a battery lor other source of ,`c'urrent, the vibratory armature vibrates,

alternately breaking and making the circuit ofl the magnetizing coil at the cooperative contact terminals 1S, 21, while the condenser 8 felectrically connected across those terminals suppresses thesparks thereat. The springy and light 4weight character oi the vibratory armature, together with its shape and the accuracy to which the parts may be readily adjusted and maintained in that adjustment, results in a vibrator-y movement of a 'frequency which is high compared with that of. the customary types of electromagnetic vibrators. Furthermore, as a result of 'the loose fit existing between the vibratory armature and the groovel 15 of the support,

:natif/ee,

the vibratory armature rotates during its vibration. Freezing or sticking of the cooperative contact terminals is therebyT prevented, and as a result of the uniform `Wear of the contact surfaces the vibrator operates over prolonged periods without requiring adjustment or renewal.

It will be observed that the construction herein disclosed is well adapted for convenience in assembly and for inspection and repair. The installation or removal of the hood does not disturb any of the working parts of the vibrator, and the adjustment of the cooperative contact terminals and for the throw of the vibratory armature are readily accessible when the hood is removed. Furthermore, the shuttle-shaped magnetic core provides for the compact embodiment of the condenser and magnetizing coil, and for sturdy connection to the housing.

Having thus described our invention, what We claim is:

1. In an electromagnetic vibrator, a shut` mounted on the cross bar and electrically connected in circuit with the contact terminals, the side flanges of the core extending above and below the magnetizing coil, and a condenser electrically connected across the contact terminals and fastened in place between the magnetizing coil and the pole pieces. y

2. In an electromagnetic vibrator, a magnetic core comprising a cross bar and end anges integral therewith, pole pieces fastened at one end of the side flanges and forming an air gap in the magnetic circuit, a vibratory armature designed to bridge the air gap andl carrying a contact terminal, a cooperative contact terminal, a magnetizing coil mounted on the cross bar and electrically connected in circuit `with the contact terminals,y a condenser electrically connected across the contact terminals and fastened in place between the cross bar and pole pieces, and a housing comprising a base fastened to the other ends of the side flanges of the core and a hood fastened to the base.

3. In an electromagnetic vibrator, an electromagnet having a. magnetizing coil, a. vi-

bratory armature rotatably supported with and rotary movements relatively thereto, a

contact terminal mounted on the vibratory armature, a cooperative Contact terminal fastened to the support in adinstable position relatively to the vibratory armature, and a magnetizing coil electrically connected. in circuit with the Contact terminals.

In an electromagnetic vibrator, a inagnetic re having pole pieces toi-ming a gap in the magnetic circuit, a support adjustabiy connected to the core, a vibratory armature comprising a diaphragm connected at opposite points to the support and an iron button 'fastened to the diaphragm in position to bridge the gap, a contact terminal carried by 'the vibratory armature, a coeperative contact terminal adjnstably connected to the support, and a magnetizing coil electrically connected. in a circuit with the contact terminals.

6. In an electromagnetic vibrator, a magnetic core, a. support having a continuous groove` a vibratory 'armature loosely fitted in the groove of the support, a contact terminal carried *by the Vibratory armature, a cooperative contact terminal carried by the support? and a. inagnetizing coil connected in circuit with the contact terminals.

.7. in an electromagnetic vibrator, a magnetic core, a support having ccntinuons groove., -shapecl vibratory armature havin@ its end flanges loosely fitted in the groove snppcrt, contact terminal carried by the ifibrajtory armature, a c perative con- "fzct terminal carried by the support, and a 'ng coil connected in circuit with mircls armature comprising diaconnected in circuit with the contact terminals, and a substantially watertight housing comprising a fastened to the core and having a beveled seat and a hood in screwthreaded engagement with the base and having a tapered end portion contacting with the beveled seat to form a substantially 'watertight j oint.

10. In an electromagnetic Vibrator, a magnetic core, a. vibrator-y arma-ture responsive to magnetic attraction of the core and carrying a contact terminal, a coperative contact tefininai. magnetizing coil electrically connected in circuit with the contact terminals, and a. housing comprising a base portion and a hood detachably connected thereto, said base carrying an insulating support for the core and having a, continuons recess in proximity to the joint with the support for deflecting Water therefrom in testimony whereof We aiix ouigsignatures, in prese ce of two witnesses.

WOLFGANG E. SOHWARZMANN. CHARLES M. WILD.

"Witnesses:

FRANZ SCHABARUM, AnonLeH H. 

